1. Field of Invention
This invention pertains to information storage, and particularly to replicating the stored contents of a hard disk drive on another hard disk drive.
2. Related Art and Other Considerations
Computers have processors, such as a microprocessor, which execute coded instructions to perform various operations. Some of the coded instructions are operating system programs which are necessary to operate the computer generally. Others of the coded instructions may be application programs which are executed in the context of the operating system programs to perform specific tasks, typically interactively, for the user, e.g., word processing programs, telecommunication programs, financial programs, etc.
In conjunction with its operation, the processor of the computer requires a memory for various purposes. For example, a computer requires memory for storing the operating system programs, for storing the application programs, and for storing data (typically in the form of files) generated by the user in the course of execution of the application programs. Some of the memory is in the form of a semiconductor chip such as a random access memory (RAM). Although instructions and/or data in chip type memory are advantageously readily accessible to the processor, such memory is generally quite expensive and of limited capacity.
Therefore, most of the memory utilized by a computer is in the form of non-semiconductor memory. Non-semiconductor memory is typically slower but less expensive than chip type memory. Perhaps the most prominent type of non-semiconductor memory is a disk which usually resides in the same enclosure or housing with the circuit board(s) upon which reside e.g., the chip type memory and the processor. The disk is commonly termed a "hard disk", and traditionally is a magnetic disk (although recently optical disks are becoming common). Recording of information on the disk and retrieval of information from the disk is performed by a unit known as the disk drive. The microprocessor usually works through a special electrical circuit or chip known as a drive interface for communicating with the drive.
Other types of non-semiconductor memory are typically accessed by a computer as well, such as floppy disks and magnetic tape. In the case of magnetic tape, recording and reproducing operations are performed by a tape drive. The tape drive is typically connected to the microprocessor through a special interface or port. Tape drives have been utilized for storing information of various types, including storing a back-up copy of some or all of the contents of a computer's hard disk. While historically tape drives have been external to the computer enclosure or housing, more recently internal tape drives have been introduced, such as the Eagle.TM. family of tape drives manufactured by Exabyte Corporation.
From time to time it may be desired or necessary to copy the contents of a computer's existing hard disk onto another hard disk (e.g., a new hard disk). Such can occur, for example, in the case of a forensic investigation in which a suspect's hard disk is examined for obtaining evidence possibly pertinent to a criminal activity. In such copying of a hard disk, the suspect's hard disk must not be contaminated during the copying procedure. Moreover, there must be assurances that the information obtained from the suspect's hard disk is authentic and accurate. Despite these constraints, it is nevertheless desirable that the copying be convenient for the forensic user or expert who performs the copying and/or analysis.
What is needed therefore, and an object of this invention, is a way for authentically replicating the image of a first hard disk onto a second hard disk without interfering with the first hard disk.